1. Field of the Invention
This invention relates to sealing rings made from rigid polymers. More specifically, the present invention relates to seal rings which can be used in static, reciprocating and rotating applications to perform a sealing function. Such rings are used in applications where fluids in the form of liquid or gas are isolated, such that the fluid exerts pressure against the seal ring thereby creating a sealed surface.
2. Background of the Invention
As is generally known, such rings have been made out of various materials, most commonly made from metals such as cast iron, flexible elastomers, and various polymers. Since the ring is placed in a groove of a piston or shaft, a gap must be placed in the ring so as to facilitate application of and removal from the piston or shaft. The known methods for preparing gaps in these rings have been to machine in the case of metals and polymers and to cut in the case of flexible polymers. Both machining and cutting of such rings has been both tedious and labor intensive, resulting in higher part costs. Likewise, when a ring has been machined, material is actually removed from the ring such that when the machined edges are brought back into contact with each other, the ring is then "out of round."
In U.S. Pat. No. 3,720,418 to Berg, a method for fracturing a ring is described wherein a "notch" is first etched or scored into the outer surface of a ring, and then the notched area is struck with a heavy object to create the fracture. Notching of the ring surface before fracturing usually results in a groove being permanently left in the outer surface of the fractured edge. A groove in the outer surface from etching or scoring, as well as deformation of the ring from machining, results in an escape route for the pressurized fluid.
The need exists for a sealing ring of a rigid polymer which is inexpensive to manufacture and is easily installable without sacrificing sealing quality.